1. Department of Biology, McGill University, 1205 Docteur Penfield, Montreal, Canada H3A 1B1
2. Smithsonian Tropical Research Institute, Gamboa, Panama
3. Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
4. School of Biological Science, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK